<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        
        .box {
            display: inline-block;
            margin: 100px;
        }
        
        .hd li {
            display: inline-block;
            width: 60px;
            text-align: center;
            cursor: pointer;
        }
        
        .hd .current {
            background: pink;
        }
        
        .bd {
            margin-top: 30px;
        }
        
        .bd>div {
            display: none;
            font-size: 18px;
            font-weight: bold;
        }
    </style>
</head>

<body>
    <div class="box">
        <div class="hd">
            <ul>
                <li class="current">1</li>
                <li>2</li>
                <li>3</li>
                <li>4</li>
            </ul>
        </div>
        <div class="bd">
            <div style="display: block;">1</div>
            <div>2</div>
            <div>3</div>
            <div>4</div>
        </div>
    </div>

    <script>
        let tabs = document.querySelector('.hd').querySelectorAll('li');
        let contents = document.querySelector('.bd').querySelectorAll('div');
        for (let i = 0; i < tabs.length; i++) {
            tabs[i].onclick = function() {
                for (let j = 0; j < tabs.length; j++) {
                    tabs[j].removeAttribute("class");
                    contents[j].removeAttribute("style");
                }
                this.className = "current";
                contents[i].style.display = "block";
            }
        }
    </script>
</body>

</html>